997 research outputs found

    Collective clusterization effects in light heavy ion reactions

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    The collective clusterization process, proposed for intermediate mass fragments (IMFs, 4<<A≤\le28, 2<<Z≤\le14) emitted from the hot and rotating compound nuclei formed in low energy reactions, is extended further to include also the emission of light particles (LPs, A≤\le4, Z≤\le2) from the fusion-evaporation residues. Both the LPs and IMFs are treated as the dynamical collective mass motion of preformed clusters through the barrier. Compared to IMFs, LPs are shown to have different characteristics, and the predictions of our, so-called, dynamical cluster-decay model are similar to those of the statistical fission model.Comment: 4 pages, 3 figures, Conferenc

    Cluster-decay of hot 56^{56}Ni∗^* formed in 32^{32}S+24^{24}Mg reaction

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    The decay of 56Ni∗^{56}Ni^*, formed in 32S+24Mg^{32}S+^{24}Mg reaction at the incident energies EcmE_{cm}=51.6 and 60.5 MeV, is calculated as a cluster decay process within the Preformed Cluster-decay Model (PCM) of Gupta et al. re-formulated for hot compound systems. The observed deformed shapes of the exit channel fragments are simulated by introducing the neck-length parameter at the scission configuration, which nearly coincides the 56Ni^{56}Ni saddle configuration. This is the only parameter of the model, which though is also defined in terms of the binding energy of the hot compound system and the ground-state binding energies of the various emitted fragments. The calculated s-wave cross sections for nuclear shapes with outgoing fragments separated within nuclear proximity limit (here ∼\sim0.3 fm) can be compared with the experimental data, and the TKEs are found to be in reasonably good agreement with experiments for the angular momentum effects added in the sticking limit for the moment of inertia. Also, some light particle production (other than the statistical evaporation residue, not treated here) is predicted at these energies and, interestingly, 4He^4He, which belongs to evaporation residue, is found missing as a dynamical cluster-decay fragment.Comment: 13 Pages, 12 figure

    Programming models for sensor networks: a survey

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    Sensor networks have a significant potential in diverse applications some of which are already beginning to be deployed in areas such as environmental monitoring. As the application logic becomes more complex, programming difficulties are becoming a barrier to adoption of these networks. The difficulty in programming sensor networks is not only due to their inherently distributed nature but also the need for mechanisms to address their harsh operating conditions such as unreliable communications, faulty nodes, and extremely constrained resources. Researchers have proposed different programming models to overcome these difficulties with the ultimate goal of making programming easy while making full use of available resources. In this article, we first explore the requirements for programming models for sensor networks. Then we present a taxonomy of the programming models, classified according to the level of abstractions they provide. We present an evaluation of various programming models for their responsiveness to the requirements. Our results point to promising efforts in the area and a discussion of the future directions of research in this area.

    Shell closure effects studied via cluster decay in heavy nuclei

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    The effects of shell closure in nuclei via the cluster decay is studied. In this context, we have made use of the Preformed Cluster Model (PCMPCM) of Gupta and collaborators based on the Quantum Mechanical Fragmentation Theory. The key point in the cluster radioactivity is that it involves the interplay of close shell effects of parent and daughter. Small half life for a parent indicates shell stabilized daughter and long half life indicates the stability of the parent against the decay. In the cluster decay of trans lead nuclei observed so far, the end product is doubly magic lead or its neighbors. With this in our mind we have extended the idea of cluster radioactivity. We investigated decay of different nuclei where Zirconium is always taken as a daughter nucleus, which is very well known deformed nucleus. The branching ratio of cluster decay and α\alpha-decay is also studied for various nuclei, leading to magic or almost doubly magic daughter nuclei. The calculated cluster decay half-life are in well agreement with the observed data. First time a possibility of cluster decay in 218U^{218}U nucleus is predicted

    Binarized Convolutional Neural Networks with Separable Filters for Efficient Hardware Acceleration

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    State-of-the-art convolutional neural networks are enormously costly in both compute and memory, demanding massively parallel GPUs for execution. Such networks strain the computational capabilities and energy available to embedded and mobile processing platforms, restricting their use in many important applications. In this paper, we push the boundaries of hardware-effective CNN design by proposing BCNN with Separable Filters (BCNNw/SF), which applies Singular Value Decomposition (SVD) on BCNN kernels to further reduce computational and storage complexity. To enable its implementation, we provide a closed form of the gradient over SVD to calculate the exact gradient with respect to every binarized weight in backward propagation. We verify BCNNw/SF on the MNIST, CIFAR-10, and SVHN datasets, and implement an accelerator for CIFAR-10 on FPGA hardware. Our BCNNw/SF accelerator realizes memory savings of 17% and execution time reduction of 31.3% compared to BCNN with only minor accuracy sacrifices.Comment: 9 pages, 6 figures, accepted for Embedded Vision Workshop (CVPRW

    Analgesic and anti-inflammatory activity of hydroalcoholic extract of Piper betle leaves in experimental animals

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    Background: Piper betle leaf, commonly known as ‘paan’ has long been known for its various medicinal properties in traditional medicine but certain properties have remained less explored. We tried to assess the analgesic and anti-inflammatory activities of Piper betle leaves.Methods: Hydroalcoholic extract of Piper betle leaves (HEPBL) was extracted using soxhlet apparatus and its phytochemical analysis was performed. Wistar rats and Albino mice were used for all the experiments. Acute toxicity study was also done according to OECD guideline no.425 and the test doses were decided accordingly. The experimental models of tail-flick method and acetic acid induced writhing were used to study the analgesic activity whereas carrageenan induced paw edema and cotton pellet granuloma models were used for anti-inflammatory action. Statistical analysis was performed using one-way analysis of variance (ANOVA) followed by Dunnett's test.Results: HEPBL showed significant analgesic activity at the doses of 100 mg/kg and 200 mg/kg, and showed significant anti-inflammatory activity at the doses of 50 mg/kg, 100 mg/kg and 200 mg/kg. The sub-therapeutic dose of HEPBL at 50 mg/kg also potentiated the analgesic effect of sub-therapeutic doses of standard analgesics. The analgesic and anti-inflammatory activity of P.betle may be attributed to the presence of various phyto constituents’ viz. flavonoids, tannins, phenols and glycosides.Conclusions: HEPBL has significant analgesic and anti-inflammatory activity in experimental animals in our study

    Dynamical cluster-decay model for hot and rotating light-mass nuclear systems, applied to low-energy 32^{32}S + 24^{24}Mg →56\to ^{56}Ni reaction

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    The dynamical cluster-decay model (DCM) is developed further for the decay of hot and rotating compound nuclei (CN) formed in light heavy-ion reactions. The model is worked out in terms of only one parameter, namely the neck-length parameter, which is related to the total kinetic energy TKE(T) or effective Q-value Qeff(T)Q_{eff}(T) at temperature T of the hot CN, defined in terms of the both the light-particles (LP), with A≤A \leq 4, Z ≤\leq 2, as well as the complex intermediate mass fragments (IMF), with 424 2, is considered as the dynamical collective mass motion of preformed clusters through the barrier. Within the same dynamical model treatment, the LPs are shown to have different characteristics as compared to the IMFs. The systematic variation of the LP emission cross section σLP\sigma_{LP}, and IMF emission cross section σIMF\sigma_{IMF}, calculated on the present DCM match exactly the statistical fission model predictions. It is for the first time that a non-statistical dynamical description is developed for the emission of light-particles from the hot and rotating CN. The model is applied to the decay of 56^{56}Ni formed in the 32^{32}S + 24^{24}Mg reaction at two incident energies Ec.m._{c.m.} = 51.6 and 60.5 MeV. Both the IMFs and average TKEˉ\bar{TKE} spectra are found to compare reasonably nicely with the experimental data, favoring asymmetric mass distributions. The LPs emission cross section is shown to depend strongly on the type of emitted particles and their multiplicities
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